Universal Serial Bus (USB) over the recent years has become a very popular interface standard for communication between host and external devices. This is primarily due to the hot swapping and plug and play feature of the USB which brings ease of use. USB was initially designed for computers to connect peripherals such as mouse, keyboard, printer, and flash drives. However, it has now become a de-facto standard on numerous electronic devices such as cell phones, smart phones, personal media players, webcams, digital cameras and USB hard drives.
A USB connection is between a USB host and a USB client device. An example is the computer which is a host and a USB flash drive which is a client. The two are connected physically through a receptacle (socket) and plug arrangement whereby a USB client has a plug type connector and USB host the corresponding socket type connector. The host side connector, being a socket, is normally covered, for example USB host ports in a computer. Whereas, the plug connector of a USB flash drive needs to be exposed so it can be plugged into a host socket. A USB cap is used to cover the exposed part of the plug connector, when not in use. The USB cap is a passive part made usually of plastic or metal. One shortcoming with existing USB devices is that aside from covering the plug connector, the USB cap does not provide any other function and hence it is an underutilized part of the USB configuration. If the cap can be made to provide additional function(s) it can enhance the benefit of the overall USB system.
Nowadays, a portable USB device usually exhibits a number of additional functions beside its primary purpose. For example, a USB based MP3 player may also be a FM radio receiver and may also be used as a USB flash drive for storage. However, a drawback of these existing multi-function USB devices is that they usually require a complex selection mechanism for configuring the device to operate in a particular mode. The mechanism can be cumbersome and use buttons or combination of buttons and a menu system. For example, the user on powering the unit may need to look up at options available on a small LCD display, scroll the list up/down or left/right and then select the desired mode. This selection process thus can be awkward and difficult at times. Since, the size of USB devices is small it is desired that the mode selection method of a multi-function USB device is as simple as possible with minimum user intervention.
It is frequently desired by users to transfer media contents such as music tracks or photographs from one portable device to another to share them with friends and family members. However, the current sharing process is often time consuming and usually involves a computer in-between. For example, if a person wants to share music on his USB based MP3 player with a friend who has an iPod.RTM., the MP3 player first needs to be connected to a computer. The songs are then copied from the MP3 player to a particular location or directory in the computer, and are finally synced to the iPod using media management software such as iTunes. Such a process for sharing media content adds complexity and limitation to the portable USB device since it cannot be used outside of the computer environment. Therefore, there is a need for a portable device which has a simple mechanism for instant media sharing.